The 4h take-home will narrow your funnel a lot. Most senior people will not do a free 4-hour take home. Try replacing it with a 2-hour interview by 3 people (th

The 4h take-home will narrow your funnel a lot. Most senior people will not do a free 4-hour take home. Try replacing it with a 2-hour interview by 3 people (that is, three 40-minute interviews each). One interviewer can do a hypothetical design question and the two others can do a programming question each. These do not have to be very difficult, but only to ensure that you are not hiring an architecture astronaut. If they can code and can explain a coherent design + some followup questions, the hiring manager can do a resume deep-dive and behavioral questions (all 4 people must be alert to behavioral cues). EDIT: For a devops person, you could do one programming interview, one design interview, and another interview of various subject-specific technologies including networking, access control, alerting/monitoring and database management.